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Space Science

Neutron Stars May Have Diamond Cores 20

Waffle Iron writes: "This article at Scientific American postulates that neutron stars may contain a quark mixture that resembles a transparent diamond instead of the metal-like mixture assumed up to now. I wonder what it would look like inside, given that the light rays would be bent into strange paths by the intense gravity. Maybe it just doesn't matter, because this is one place that nobody will ever get to see."
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Neutron Stars May Have Diamond Cores

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  • by Anonymous Coward
    My understanding as an advanced Student of physics is that the characteristic length scales at which quarks are bound and their "intrinisic" (rest mass energy wavelength) size make then highly unlikely to "vibrate" in the comparably much larger (6+ orders of magnitude) range of visible light, and thus they won't absorb of emit visible light to any significant degree.
  • I too started noticing SciAm getting all "wired" on us about 3 years ago and have since watched it get progressively worse. It's really a shame.

    It started long before that. Ad pages began dropping in the 70s and continued in the 80s. Since ad pages is a decent measure of the profitability of a magazine, I thought SciAm was a goner. They've retooled the look of the magazine and some of the content and their readership has gone back up. Sure I preferred the old SciAm, but the magazine was dying.

    These days, you tend to get more articles written by science journalists and not as many by the researchers themselves. On the other had, it used to be the case that I could read and understand an average of two complete articles a month. Now that average has gone up significantly. I still learn new science from SciAm, but it is not the same magazine that it once was.

    Face it. There just wasn't a big enough market for the old Scientific American.
  • Although it might be in crystalline form, neutronium is a substance made of pure neutrons ...

    At the gravity/density found in neutron stars protons and electrons are squeezed together creating neutrons. Ordinary matter, a proton/neutron nucleus orbited by a cloud of electrons, ceases to exist.

    As I recall, one tablespoon of this "diamond" would weigh as much as Manhattan Island. :)


  • are considerably more likely to have cores of diamond because they are hot, pressure is very high, and the chemical component for diamond is in abundance -- carbon. The core conditions of these worlds don't come anywhere close to the conditions found in a neutron star because a neutron star is not ultimately made by the kind of process which forms planets. Planets do not have gravity capable of overcoming the repulsive force (strong nuclear force, I do not remember the term?) that exists between positive and negative atomic particles. As far as we know any one trillion ton teaspoon of neutronium is the same as another trillion ton teaspoon of neutronium, precluding anything resembling chemistry.

    I *AM* somewhat curious as to the hardness of neutronium. I suspect there would be no way of measuring it, but then again artificially producing it would probably prove extremely difficult, if not impossible.


  • Heh, I was responding to the title of the /. article. If the article has been this deeply ridiculed just from the comments I really have no interest in going to the site to read the source. Whether neutron star core neutronium is opaque, translucent, or has pretty pink spots is truly getting into the realm of absurdity. I suspect it has no bearing whatsoever on anything we are likely to do or encounter for the next millenium or so. :)

    Thanks for the correction regarding forces, I seldom have the opportunity to discuss them, and being a dabbler as opposed to one dedicated to the study of physics I knew the nature of the force if not the name of the force involved.

    I do not believe there is a way for us to artificially create the kind of pressures required to generate neutronium, unless we were to use something like focused shockwaves from thermonuclear detonations, which would probably destroy any instruments we might use to capture the end product of the experiment. :)

    Thanks again for your comments.


  • "Maybe it just doesn't matter, because this is one place that nobody will ever get to see."

    --
    Spelling by m-w.com [m-w.com].

  • I used to love reading scientific american in the 80's but by the mid-90s they have been Discoverized and had dumbed down their articles and the magazine was mostly ads. I was lucky to get a gift subscription to 'Science News' a couple of years ago for Christmas and have been a subscriber ever since - it's a fantastic science weekly with a good content level - check it out at www.sciencenews.org --Vince
  • by rellort ( 146793 ) on Monday April 16, 2001 @07:55PM (#287114)
    I don't blame them for selling out. Seems all serious science journals eventually go the route of pop science. How much money can you really make selling ad space for digital multimeters after all? At some point, you have to go a little mainstream and start selling space to General Motors.

    You can't do that with articles that don't appeal to the general public. More specifically, the part of the general public who thinks they're several notches in intelligence above the "rest" of the general public.

    So SciAm strokes their ego with headlines about diamond cores. Maybe they give them some nice sidebar explanations of the unfamiliar (to them) astronomy terms. It's stuff the quasi-average reader can relate to. At the same time, many of us long for the days when the magazine covered hard science. You know, the kind of stuff you didn't even try to grasp without a PhD.

    So Scientific American is dead. Long live Scientific American.
  • I too started noticing SciAm getting all "wired" on us about 3 years ago and have since watched it get progressively worse. It's really a shame.

    SciAm used to be a refuge for what I had assumed to be the huge demographic of highly scientifically literate geeks who do NOT have doctorates in particle physics (IE. people like me). But, with reporting like this [sciam.com], that's just plain stinking with blatant scientific inaccuracies, it's too late it seems. You've gone the way of Discover and New Scientist, never to return to the pinnacle of respectable scientific journalism you once defined.

    Time to let my subscription run out and get some Nature or Science in it's place.

  • My thought was that the quarks in the neutron star, not being confined to a nucleus, would have sufficient freedom to absorb or emit longer wavelengths. But I guess that even though they exist a very large volume, each individual quark still has a fairly well determined position, and hence has widely separated energies.
  • by caffeinated_bunsen ( 179721 ) on Monday April 16, 2001 @10:29PM (#287117)
    The title of 'diamond' is highly suspect. Matter at the middle of a neutron star doesn't even bother forming nuclei, much less atoms or crystals. What they're saying is that the quark soup in a neutron star was previously thought to contain a few electrons mixed in, which would absorb light. It now seems that strange quarks are more stable in that environment than previously thought, which eliminates the requirements for electrons in that area. The result is a whole hell of a lot of mass in a small volume that doesn't interact with light all that much. So if you managed to isolate the core of a neutron star (completely impossible), without changing its optical properties (even more impossible), you'd have a transparent object the size of a small city, weighing as much as a small star.

    The fact that strange quarks may be more stable than previously thought under some circumstances is interesting. The fact that some portion of the middle of a neutron star is transparent is almost completely useless speculation. Ignoring that, there's still the problem that nothing in the article remotely resembles a diamond from a scientist's point of view.

    What I'm not so sure about is why it is supposed to be transparent. I know that all macroscopic interaction we observe with light is through electrons, but I thought that was just because the nuclei take up too little space to be noticed. When you have a star core composed of quarks, even without electrons mixed in, I'd expect electromagentic interaction with the quarks themselves to prevent light from travelling any distance. Or are the quarks bound tightly enough that they can't absorb or emit visible wavelengths? IANANPY (I am not a nuclear physicist, yet), so I'm not so sure about that one.

  • I am an Engineering Physics student at Cornell University, and I plan on eventually plan on obtaining my PhD, and I appreciate magazines that can quickly summarize new research without using prohibitive quantities of jargon. I somehow doubt Scientific American is trying to appeal to "dumb" people, only those with less than 10 years of research experience in the field involved! Journals like Nature provide in-depth, technical information for those so inclined. For those who are not, yet have the interest and wish to be informed without wading through pages of unnecessary details and obfuscating terminology, there is Scientific American. I will be publishing a paper with my advisor on research I've done with computer simulations of plasma jets from accretion disks. No one I know (other than professors here at Cornell) can understand the paper, in fact I do not think I would understand it if I had not done the research myself! Yet the concepts behind it are actually not too difficult to understand, assuming they are actually explained to the reader.

    So I say save the hard-science PhD prerequisite stuff for journals like Nature, and allow those who have not had the oppertunity to obtain a PhD to get their science news from magazines like SciAm. Young scientists-to-be deserve to know what is going on in the scientific community too. Science is for all who seek truth and understanding of the universe, not simply those fortunate to have obtained a doctorate.

    Just my two cents.
  • If you'd have read the posts or the article, you'd have found out that the word "diamond" was being used very figuratively. Neutron stars may have DIAMOND-LIKE crystaline structures. They used "diamond" in the title as a buzzword, thus making the article stick out more. People think "big diamond, wow... I want one" and read the article.

    The strong nuclear force is the force between hadrons (particles composed of quarks, like protons and neutrons). Planets do not have gravity capable of overcoming the repulsive force of ELECTROMAGNETISM, which is respulsive only because the nuclei are positively charged (try sticking two like ends of a magnet together, pretty tough sometimes). To create neutronium, you basically have to do a massive-scale fusion reaction (usually caused by gravity) that creates one giant nucleus. And they are saying in the article that it's thought that the structure of the neutronium would be such that it would be transparent at visible wavelengths. That's all.

    As for hardness, you have to remember it's only stable at those pressures. How you test hardness of something under super-high pressure, I honestly don't know.

    Just my two cents.
  • I'd like to see the DeBeers' own that!
  • Although I don't see why matter has to be "diamond-like" once it's been determined that it is not metallic. Why can't they just compare it to glass?
    The Physical Review Letters article might be worth reading but the SciAm blurb is a badly misleading popularization. People are going to think neutron stars are made of ordinary carbon diamond- which is the worst possible impression to give. It's so bad it's not even wrong! Neutron stars are far more interesting [umd.edu] than diamonds are. You would never find anything resembling ordinary matter (atoms, nuclei, shells, etc.) in a neutron star, or even in a white dwarf.
  • Paging Arthur C. Clarke... Paging Mr. Clarke... There's a delivery for you. Plot line delivery for Mr. Clarke...

    OK,
    - B
    --

  • Although the star's core would be neither solid nor crystal nor faceted, apparently it would reflect some light at its boundaries and otherwise resemble a diamond

    So last I checked, we'd call that "carbon" right? I mean, if it's a big, non-crystaline chunk of carbon, it's not a diamond right? That's at least my understanding of what a diamond is....

    This has been another useless post from....
  • Yeah, that reminds me of the planet from "The Hitch Hiker's Guide to the Galaxy" whose "core" created planets. They must have made these nuetron stars as defense against space pirates. Maybe not but its worth pondering.
  • Oh yeah, that's informative.

    When moderation costs you karma only karma whores will moderate. Or something like that.

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